Liquid crystal display device and method for manufacturing the same

ABSTRACT

Disclosed are an LCD device and a method of manufacturing the same, in which a passivation layer and a pixel electrode are simultaneously formed by a single mask process using a half tone mask, and thus, manufacturing efficiency increases, and a defective contact due to loss of the pixel electrode can be prevented in a pad area. The LCD device includes a pad part including a pad area and a contact area. The LCD device includes a pixel pad formed in the pad area, a pixel bar formed in the contact area, and a bridge layer contacting the pixel pad with the pixel bar. The bridge layer is formed as a single layer or multi layers, and formed of one or more of a transparent conductive material and an opaque conductive material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is divisional application of U.S. patent application Ser. No.13/627,589 filed on Sep. 26, 2012, which claims the priority benefit ofthe Korean Patent Application No. 10-2011-0097759 filed on Sep. 27,2011, and of Korean Patent Application No. 10-2011-0097760 filed on Sep.27, 2011. All of the above prior U.S. and Korean patent applications arehereby incorporated by reference as if fully set forth herein.

BACKGROUND Field of the Invention

The present invention relates to a liquid crystal display (LCD) device,and more particularly, to an LCD device and a method of manufacturingthe same, in which a passivation layer and a pixel electrode aresimultaneously formed by a single mask process using a half tone mask,and thus, manufacturing efficiency increases, and a defective contactdue to loss of the pixel electrode can be prevented in a pad area.

Discussion of the Related Art

Recently, in applying a touch sensor (screen) to LCD devices, a liquidcrystal panel with integrated touch sensor is developed for slimming.Particularly, an in-cell touch type LCD device that uses a commonelectrode (which is formed on a lower substrate) as a touch sensingelectrode is developed.

FIG. 1 is a view illustrating a related art LCD device. FIG. 2 is a viewillustrating a pixel structure of the related art LCD device.

In FIGS. 1 and 2, the structure of a thin film transistor (TFT) arraysubstrate (lower substrate) is illustrated in the fringe field switch(FFS) mode, and it is illustrated that a touch sensor is built in theTFT array substrate in an in-cell touch type.

In FIGS. 1 and 2, a color filter array substrate (upper substrate), aliquid crystal layer, and a driving circuit part for driving a liquidcrystal panel are not illustrated.

An active area 1 for displaying an image is formed at the TFT arraysubstrate, and a plurality of pad parts 3 to 5 are formed in an inactivearea formed at an outer portion.

A plurality of pixels are formed in the active area 1.

The pad part 3 is a unit on-off pad part, the pad part 4 is a unit FPCpad/unit FPC shorting connection part, and the pad part 5 is a bumpinput dummy/bump output dummy part.

In FIG. 1, the pad part is illustrated as being formed at an outerportion of an upper end of the panel, but may be formed at an outerportion of each of a left side, right side, and lower end of the panel.

The pixels formed in the active area are defined by intersection betweena plurality of data lines (not shown) and gate lines (not shown),respectively. A TFT is formed in each of a plurality of areas defined byintersection between the data lines and the gate lines.

Referring to FIG. 2, each pixel of the related art LCD device includes aTFT, a common electrode 60, and a pixel electrode 90 that are formed ona glass substrate 10.

Specifically, each pixel includes a light shield 20, a buffer layer 22,a TFT, a gate insulator (GI) 36, an inter-layer dielectric (ILD) 40, aplurality of passivation layers (PAS1 and PAS2) 50 and 80, a datacontact 45, a common electrode 60, a touch sensing line 70, and a pixelelectrode 90.

The TFT is configured with an active 30, a source 32, and a drain 34that are formed under the gate insulator 36, and a gate 38 formed on thegate insulator 36.

The touch sensing line 70 is formed on the common electrode 60 to crossthe pixels, and connects the common electrodes 60 of the respectivepixels.

Here, the common electrode 60 supplies a common voltage (Vcom) to acorresponding pixel during a display period, and performs the functionof a touch sensing electrode for detecting a touch during a non-displayperiod.

Each pixel having the above-described structure is formed by amanufacturing method illustrated in FIG. 3.

FIG. 3 is a view for describing limitations of a related art method ofmanufacturing an LCD device. In FIG. 3, a view of a manufacturing methodfor forming a plurality of layers formed under the inter-layerdielectric 40 is not illustrated.

Referring to FIG. 3, a first passivation layer (PAS1) 50 is formed ofphoto acryl, on the inter-layer dielectric 40. A first contact hole 55is formed by etching an area that overlaps the data contact 45. Here,the first passivation layer 50 is formed to a thickness of 3 um, and atop of the data contact 45 is exposed by the first contact hole 55.

Subsequently, the common electrode 60 is formed of a transparentconductive material such as indium tin oxide (ITO) or indium tin zincoxide (ITZO), in a pixel area in a top of the first passivation layer50.

Subsequently, the touch sensing line 70 is formed on the commonelectrode 60, and connects the common electrodes 60 of adjacent pixels.

Subsequently, a second passivation layer (PAS2) 80 is formed on thefirst passivation layer 50 to cover the common electrode 60 and thetouch sensing line 70.

Subsequently, the second passivation layer (PAS2) 80 is etched to exposea top of the data contact 45 by performing an etching process and aphotolithography process using a half tone mask, thereby forming asecond contact hole 85.

Herewith, a photoresist (PR) 95 is coated on the second passivationlayer 80, and a pixel electrode layer is formed of ITO, indium zincoxide (IZO), or ITZO on the photoresist 95 for forming a pixelelectrode.

Subsequently, the pixel electrode layer is patterned, the photoresist 95is ashed, and then a pixel electrode 90 is formed in a finger shape byperforming a lift-off process.

In this case, the pixel electrode 90 is formed in a finger shape on thesecond passivation layer 80 by using a half tone area of the half tonemask. Furthermore, the second passivation layer 80 in an areaoverlapping the data contact 45 is etched using a full tone area of thehalf tone mask. By forming the pixel electrode 90 in a second contacthole 85, the data contact 45 contacts the pixel electrode 90.

In the related art LCD device manufactured by the above-describedmanufacturing method, the first passivation layer 50 is thickly formedto a thickness of 3 um, and the photoresist 95 is coated to a thicknessof 2 um to 3 um.

In coating the photoresist 95, due to planarization characteristic, thethickness of the photoresist 95 formed in a portion corresponding to thefull tone area is thickened to 5 um to 6 um. In this case, in amanufacturing process, the photoresist 95 coated for forming the pixelelectrode 90 may not all be removed through an ashing process but may bepartially left in a contact hole.

Specifically, by adding the thickness (3 um) of the first passivationlayer 50 to a target thickness (0.5 um to 1.0 um) of the half tone area,the photoresist 95 is partially left to a thickness of 3.5 um to 5.5 umin a side wall portion of the contact hole.

With the photoresist 95 being partially left, by performing the lift-offprocess, the photoresist 95 is stripped in the contact hole, causing theloss of the pixel electrode 90.

The photoresist 95 is ashed, and then, by performing the lift-offprocess, the photoresist 95 that is left in the contact hole is removed,and simultaneously the pixel electrode 90 formed in the contact hole isremoved together with the photoresist 95.

FIG. 4 is a view for describing disconnection of a pixel bar that occursin a pad part of the related art LCD device. In FIG. 4, the unit on-offpad part 3 among the pad parts 3 to 5 is illustrated.

Referring to FIG. 4, the unit on-off pad part 3 among the pad parts 3 to5 includes a plurality of pads 12 and pixel bars 14.

The unit on-off pad part 3 formed in an outer portion of the panel isformed by a manufacturing process of forming a pixel, in which case thefirst contact hole 55 is formed by broadly etching the first passivationlayer 50 to a size of 250 μm. The unit on-off pad part 3 has a structurein which a pixel pad and the second contact hole 85 of the secondpassivation layer 80 are arranged in the first contact hole 55.

Connection of the pixel bar 14 is made using the first contact hole 55portion, and thus, the plurality of pixel pads 12 and the second contacthole 85 are arranged in plurality, in the first contact hole 55.

In a manufacturing process, a pixel area with no second contact hole 85is formed using the half tone area, and thus, the pixel electrode 90formed on the second passivation layer 80 is lost in a pad areaidentically to the pixel area.

In this case, the pixel electrode 90 formed in the pad area cannot actas an electrode receiving a data voltage, unlike a pixel electrodeformed in the pixel area, and acts as a contact that connects the pixelbar 14 to the pixel pad 12.

In this way, if the pixel electrode 90 is lost in the pad area,respective signals cannot be supplied to a plurality of pixels formed inthe active area, and thus, the test of a manufactured panel is notsmoothly performed, and moreover defective driving occurs in which animage cannot normally be displayed.

FIG. 5 is a view for describing disconnection of a pixel bar that occursin a pad part of the related art LCD device. In FIG. 5, the unit FPC padpart/unit FPC shorting connection part 4 among the pad parts 3 to 5 isillustrated.

Referring to FIG. 5, the unit FPC pad part/unit FPC shorting connectionpart 4 among the pad parts 3 to 5 includes a plurality of pads 12, pixelbars 14, and power lines 16.

The unit FPC pad part/unit FPC shorting connection part 4 formed in anouter portion of the panel is formed by a manufacturing process offorming a pixel in the active area.

In a manufacturing process, the first contact hole 55 is formed bybroadly etching the first passivation layer (PAS1) 50. A plurality ofpixel pads are arranged in the first contact hole 55, and the pad 12 isconnected to the pixel bar 14.

A data voltage is supplied to a pixel electrode in a pixel area, but thepixel electrode 90 formed in a pad area is formed for performing thefunction of a contact, without receiving a data voltage. That is, thepixel electrode 90 formed in the pad area acts as a contact thatconnects the pixel bar 14 to the pixel pad 12.

In a manufacturing process, a pixel area with no second contact hole 85is formed using the half tone area of a mask. Therefore, the pixelelectrode 90 formed on the second passivation layer 80 is lost in thepad area, similarly to the pixel area.

In this way, if the pixel electrode 90 is lost in the pad area,respective signals cannot be supplied to a plurality of pixels formed inthe active area. For this reason, the test of a manufactured panelcannot smoothly be performed. Also, defective driving occurs in which animage cannot normally be displayed.

In a method that prevents the defective contact of the pixel bar 14 dueto the loss of the pixel electrode 90, there is a method that connectsthe pad 12 and the pixel bar 14 by using the metal of the touch sensingline 70 in a manufacturing process.

However, the test of the panel is completed, and then a line between thepad 12 and the pixel bar 14 is cut along a scribe line. Therefore, metalthat connects the pad 12 and the pixel bar 14 is exposed to the outside.

FIG. 6 is a view illustrating a plurality of masks that are used in aschematic manufacturing method and process of a related art LCD devicewith integrated touch sensor.

Referring to FIG. 6, a total of eleven masks are used in manufacturing aTFT array substrate with integrated touch sensor, for which a pluralityof detailed processes are performed. For example, a plurality ofprocesses of respectively forming a light shield with a mask 1, formingan active with a mask 2, forming a gate with a mask 3, forming a lightlydoped drain (LDD) with a mask 4, forming an inter-layer dielectric (ILD)with a mask 5, forming a data contact with a mask 6, forming a firstpassivation layer (PAS1) with a mask 7, forming a common electrode witha mask 8, forming a conductive line with a mask 9, forming a secondpassivation layer (PAS2) with a mask 10, and forming a pixel electrode(PXL) with a mask 11 are sequentially performed.

Especially, different masks are used in forming the common electrode andthe touch sensing line, and different masks are used in forming thesecond passivation layer (PAS2) and the pixel electrode (PXL). In thisway, in manufacturing the related art LCD device with integrated touchsensor, a number of masks are used, and thus, the manufacturing costincreases.

Moreover, since a detailed process is performed in each mask process,the manufacturing cost is high, and a time taken in manufacturing islong, causing the decrease in product competitiveness.

SUMMARY

Accordingly, the present invention is directed to an LCD device and amethod of manufacturing the same that substantially obviate one or moreproblems due to limitations and disadvantages of the related art.

An aspect of the present invention is directed to provide an LCD deviceand a method of manufacturing the same, which a passivation layer and apixel electrode are simultaneously formed by a single mask process usinga half tone mask, and thus, manufacturing efficiency increases.

Another aspect of the present invention is directed to provide an LCDdevice and a method of manufacturing the same, which can preventdisconnection, caused by loss of a pixel electrode due to a lift-offprocess, in a pad area.

Another aspect of the present invention is directed to provide an LCDdevice and a method of manufacturing the same, which can the contactperformance of a pixel bar in a pad area.

In addition to the aforesaid objects of the present invention, otherfeatures and advantages of the present invention will be describedbelow, but will be clearly understood by those skilled in the art fromdescriptions below.

Additional advantages and features of the invention will be set forth inpart in the description which follows and in part will become apparentto those having ordinary skill in the art upon examination of thefollowing or may be learned from practice of the invention. Theobjectives and other advantages of the invention may be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the invention, as embodied and broadly described herein, there isprovided an LCD device, in which a pad part including a pad area and acontact area is formed, including: a pixel pad formed in the pad area; apixel bar formed in the contact area; and a bridge layer contacting thepixel pad with the pixel bar, wherein, the bridge layer is formed as asingle layer or multi layers, and the bridge layer is formed of one ormore of a transparent conductive material and an opaque conductivematerial.

In another aspect of the present invention, there is provided a methodof manufacturing an LCD device, which includes a pad area with a pixelpad formed therein and a contact area with a pixel bar formed therein,including: forming a first passivation layer in the pad area and thecontact area, and removing a portion of the first passivation layer toform a first contact hole; forming a lower metal inside the firstcontact hole in the pad area, inside the first contact hole in thecontact area, and on the first passivation layer in the contact area;forming a second passivation layer to cover the first passivation layerand the lower metal; removing a portion of the second passivation layeroverlapping the lower metal in the pad area and removing another portionof the second passivation layer overlapping the pixel bar in the contactarea to form a second contact hole; and coating a transparent conductivematerial on the pad area to form a pixel electrode, and coating atransparent conductive material on the contact area to form a contactpattern, wherein the pixel pad and the pixel bar are connected with thecontact pattern and the lower metal.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiments of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a view illustrating a related art LCD device;

FIG. 2 is a view illustrating a pixel structure of the related art LCDdevice;

FIG. 3 is a view for describing limitations of a related art method ofmanufacturing an LCD device;

FIG. 4 is a view for describing disconnection of a pixel bar that occursin a pad part of the related art LCD device;

FIG. 5 is a view for describing disconnection of a pixel bar that occursin a pad part of the related art LCD device;

FIG. 6 is a view illustrating a plurality of masks that are used in aschematic manufacturing method and process of a related art LCD devicewith integrated touch sensor;

FIG. 7 is a view illustrating an LCD device according to an embodimentof the present invention;

FIG. 8 is a view illustrating a pixel structure of an LCD deviceaccording to a first embodiment of the present invention;

FIG. 9 is a view illustrating a pad part of an LCD device according to afirst embodiment of the present invention;

FIG. 10 is an enlarged view of a contact area of FIG. 9;

FIGS. 11 to 15 are views illustrating a method of manufacturing an LCDdevice according to an embodiment of the present invention;

FIG. 16 is a view illustrating a pixel structure of an LCD deviceaccording to a second embodiment of the present invention;

FIG. 17 is a view illustrating a pad part of an LCD device according toa second embodiment of the present invention;

FIG. 18 is an enlarged view of a contact area of the pad part of FIG.17;

FIG. 19 is a sectional view taken along line A1-A2 and line B1-B2 ofFIG. 17;

FIGS. 20 to 24 are views illustrating a method of manufacturing an LCDdevice according to an embodiment of the present invention; and

FIG. 25 is a view illustrating a plurality of masks that are used in aschematic manufacturing method and process of an LCD device withintegrated touch sensor.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Hereinafter, an LCD device with integrated touch sensor and a method ofmanufacturing the same according to embodiments of the present inventionwill be described with reference to the accompanying drawings.

In description of embodiments of the present invention, when a structure(for example, an electrode, a line, a wiring, a layer, or a contact) isdescribed as being formed at an upper portion/lower portion of anotherstructure or on/under the other structure, this description should beconstrued as including a case where the structures contact each otherand moreover a case where a third structure is disposed therebetween.

Furthermore, terms “upper portion/lower portion” and “on/under” are fordescribing the structure and manufacturing method of the presentinvention with reference to the drawings. Therefore, the terms “upperportion/lower portion” and “on/under” may differ in structure during amanufacturing process and after manufacturing is completed.

LCD devices have been variously developed in a twisted nematci (TN)mode, a vertical alignment (VA) mode, an in-plane switching (IPS) mode,and a fringe field switching (FFS) mode according to a scheme ofadjusting the alignment of liquid crystal.

In the IPS mode and the FFS mode among the modes, a plurality of pixelelectrodes and common electrode are arranged on a lower substrate, andthus, the alignment of liquid crystal is adjusted by electric fieldsbetween the pixel electrodes and the common electrodes.

In the IPS mode, particularly, the pixel electrodes and the commonelectrodes are alternately arranged in parallel, and thus, lateralelectric fields are respectively generated between the pixel electrodesand the common electrodes, thereby adjusting the alignment of liquidcrystal.

In the IPS mode, however, the alignment of liquid crystal is notadjusted in a portion on the pixel electrodes and common electrodes, andthus, light transmittance is reduced in a corresponding area.

To overcome the limitation of the IPS mode, the FFS mode has beenproposed. In the FFS mode, a plurality of pixel electrodes and commonelectrodes are formed apart from each other with an insulating layertherebetween.

In this case, the one electrodes of the pixel electrodes and commonelectrodes are formed in a plate shape or a pattern, and the otherelectrodes are formed in a finger shape, thereby adjusting the alignmentof liquid crystal with fringe fields generated between the pixelelectrodes and common electrodes.

An LCD device with integrated touch sensor (screen) according toembodiments of the present invention includes a liquid crystal panel, abacklight unit that supplies light to the liquid crystal panel, and adriving circuit part. Here, a liquid crystal panel is formed in anin-cell touch type in which a touch sensor for detecting a positiontouched by a user is built in the liquid crystal panel.

The driving circuit part includes a timing controller (T-con), a datadriver (D-IC), a gate driver (G-IC), a sensing driver, a backlightdriver, and a power supply that supplies a driving source voltage to thedrivers.

Here, all or some of the driving circuit part may be formed in a chip onglass (COG) type or a chip on film (chip on flexible printed circuit,COF), on a liquid crystal panel.

FIG. 7 is a view illustrating an LCD device according to an embodimentof the present invention. FIG. 8 is a view illustrating a pixelstructure of an LCD device according to a first embodiment of thepresent invention;

In FIGS. 7 and 8, the structure of a thin film transistor (TFT) arraysubstrate (lower substrate) is illustrated in the FFS mode. In FIGS. 7and 8, a touch sensor is illustrated as being internalized in an in-celltouch type in the TFT array substrate.

In FIGS. 7 and 8, a color filter array substrate (upper substrate), aliquid crystal layer, a backlight unit, and a driving circuit part arenot illustrated.

Referring to FIG. 7, an active area 100 displaying an image is formed ata TFT array substrate, and an inactive area is formed at an outerportion of the active area 100. A plurality of pixels are formed in theactive area 100. Furthermore, a plurality of pad parts 230, 240 and 250are formed in the inactive area 200.

The plurality of pad parts 230, 240 and 250 formed in the inactive area200 include a unit on-off pad part 230, a unit FPC pad/unit FPC shortingconnection part 240, and a bump input dummy/bump output dummy part 250.

In FIG. 7, the pad parts 230, 240 and 250 are illustrated as beingformed at an outer portion of an upper end of a panel, but may be formedat an outer portion of a left/right side of the panel and an outerportion of a lower end of the panel.

A plurality of pixels formed in the active area are defined byrespective intersections between a plurality of data lines (not shown)and gate lines (not shown). A TFT is formed in each of a plurality ofareas in which the data lines intersect the gate lines.

The plurality of pixels are formed at the TFT array substrate, anddefined by respective intersections between the data lines (not shown)and the gate lines (not shown).

A TFT is formed in each of a plurality of areas in which the data linesintersect the gate lines. Also, each of the pixels includes a commonelectrode and a pixel electrode.

Referring to FIG. 8, the TFT array substrate includes a glass substrate110, a light shield 120, a buffer layer 122, a gate insulator 136, adata contact 145, a inter-layer dielectric (ILD) 140, a firstpassivation layer 150, a common electrode 160, a touch sensing line 170,a second passivation layer 180, a pixel electrode 190, and a TFT thatincludes an active 130, a source 132, a drain 134, and a gate 138. Here,the TFT includes a lightly doped drain (LDD) 133.

In an upper portion of the glass substrate 110, the light shield 120 isformed in a TFT area, and the buffer layer 122 is formed to cover thelight shield 120. The light shield 120 may be formed of Mo or Al, andhave a thickness of 500 Å.

The buffer layer 122 may be formed of an inorganic material, forexample, SiO₂ or SiNx, and have a thickness of 2,000 Å to 3,000 Å.

The active 130, source 132, and drain 134 of the TFT are formed in anarea overlapping the light shield 120, on the buffer layer 122 in theTFT area.

Here, the active 130 may be formed of poly silicon (P—Si), and have athickness of 500 Å. The LDD 133, the source 132, and the drain 134 maybe formed by doping P-type impurities or N-type impurities on asemiconductor layer.

The gate insulator 136 is formed to cover the active 130, the source132, and the drain 134 on the buffer layer 122. In this case, the gateinsulator 136 may be formed of SiO₂, and have a thickness of 1,300 Å.

The gate insulator 136 may be formed by depositing tetra ethyl orthosilicate (TEOS) or middle temperature oxide (MTO) in a chemical vapordeposition (CVD) process.

In an upper portion of the gate insulator 136, the light shield 120 isformed in an area overlapping the active 130. In this case, the gate 138may be formed of Al or Mo, and have a thickness of 3,000 Å.

In this way, the gate 138 and the active 130, source 132, and drain 134are formed with the gate insulator 136 therebetween, thereby forming theTFT.

The inter-layer dielectric 140 is formed to cover the gate 138, on thegate insulator 136.

In this case, the inter-layer dielectric 140 may be formed of SiO₂ orSiNx, and have a thickness of 6,000 Å. As another example, theinter-layer dielectric 140 may be formed in a structure in which SiO₂(3,000 Å) and SiNx (3,000 Å) are stacked.

A portion of the gate insulator 136 and a portion of the inter-layerdielectric 140 are etched to expose a top of the drain 134, and the datacontact 145 is formed at a portion in which the gate insulator 136 andthe inter-layer dielectric 140 are etched. The data contact 145 contactsthe drain 134.

The data contact 145 contacts the drain 134 and the pixel electrode 190.In this case, the data contact 145 may be formed to have a thickness of6,000 Å, and formed in a structure in which Mo, Al, and Mo are stacked.

The first passivation layer (PAS1) 150 is formed to cover the datacontact 145, on the inter-layer dielectric 140. Here, the firstpassivation layer 150 is formed of photo acryl, and has a thickness of 3um.

The common electrode 160 is formed on the first passivation layer 150,in the pixel area.

The common electrode 160 may be formed of a transparent conductivematerial, such as indium tin oxide (ITO), indium zinc oxide (IZO), orindium tin zinc oxide (ITZO), to have a thickness of 500 Å.

The touch sensing line 170 is formed on the common electrode 160. Theconductive line 170 is formed to cross the plurality of pixels, andconnects the common electrodes 160 of adjacent pixels. Therefore, thecommon electrode 160 acts as a touch sensing electrode during anon-display period.

Here, the touch sensing line 170 may be formed of Mo or Al, and have athickness of 1,500 Å to 2,000 Å. The touch sensing line 170 may beformed in a structure in which Mo, Al, and Mo are stacked.

The touch sensing line 170 connects the common electrodes 160 ofadjacent pixels to form a touch block. In this case, the touch blockincludes a touch row block for detecting a touch position in an X-axisdirection, and a touch column block for detecting a touch position in aY-axis direction.

The touch sensor detects X-axis and Y-axis coordinates for detecting aposition touched by a user. Therefore, the touch row block and the touchcolumn block are required to be separated from each other withoutcontact therebetween.

To this end, the touch sensing line 170 in the touch column block isconnected in the Y-axis direction by using a conductive line that isformed to overlap the data line of the TFT array substrate. Therefore,the touch sensing line 170 in the touch column block enables thedetection of a position touches by a user in the Y-axis direction.

The touch sensing line 170 in the touch row block avoids contact withthe touch column block by using a bride line that is formedsimultaneously with a gate line formed on the TFT array substrate. Thetouch sensing line 170 in the touch row block enables the detection of aposition touches by a user in the X-axis direction. For example, thebridge line disposed in a central portion of the pixel to blockdisclination of the multi-domain pixel region, the bridge line beingparallel with the gate line.

As described above, the touch row block and the touch column block areseparated from each other, thereby enabling the detection of a positiontouched by a user in the X-axis direction and the Y-axis direction.

A second passivation layer 180 is formed to cover the common electrode160 and the touch sensing line 170, on the first passivation layer 150.Here, the second passivation layer 180 may be formed of SiO₂ or SiNx,and have a thickness of 2,000 Å to 3,000 Å.

A first contact hole 155 is formed in an area overlapping the datacontact 145, in the first passivation layer 150.

The second passivation layer 180 is etched to form a second contact hole185, on the first contact hole 155.

The pixel electrode 190 is formed in a finger shape in the pixel area,on the second passivation layer 180. The pixel electrode 190 is formedin the first and second contact holes 155 and 185, and contacts the datacontact 145. Through such a contact structure, the drain 134 of the TFTcontacts the pixel electrode 190 via the data contact 145.

In this case, the pixel electrode 190 may be formed of a transparentconductive material, such as ITO, IZO, or ITZO, to have a thickness of500 Å.

The second passivation layer 180 and the pixel electrode 190 may besimultaneously formed by a single mask process by using one half tonemask (HTM).

The LCD device according to an embodiment of the present inventionadjusts the transmittance of light, which passes through a liquidcrystal layer, with data voltages applied to the respective pixelelectrodes of the pixels and a common voltage applied to the commonelectrodes during a display period, thereby displaying an image realizedwith image signals.

Furthermore, the LCD device drives the respective common electrodes 160of the pixels, connected by the touch sensing line 170, as touch sensingelectrodes during the non-display period, thereby sensing the change ina capacitance (Ctc) due to a user's touch. The LCD device compares acapacitance generated by the user's touch and a reference capacitance todetect a touch position (TS).

FIG. 9 is a view illustrating a pad part of an LCD device according to afirst embodiment of the present invention. FIG. 10 is an enlarged viewof a contact area of FIG. 9.

In FIGS. 9 and 10, the unit on-off pad part 230 among the pad parts 230,240 and 250 is illustrated.

Referring to FIGS. 9 and 10, the unit on-off pad part 230 among the padparts 230, 240 and 250 includes a plurality of pixel pads 232 and pixelbars (pixel lines) 234.

The unit on-off pad part 230 formed at an outer portion of the panel isformed through a manufacturing process of forming the pixels. At thispoint, the first contact hole 155 is formed by broadly etching the firstpassivation layer (PAS1) 150. The unit on-off pad part 230 has astructure in which the pixel pads and the second contact holes 185 ofthe second passivation layer 180 are arranged in the first contact hole155.

The connection of the pixel bar 234 is made using the first contact hole155 portion. Therefore, the pixel pads 232 and the second contact holesare arranged in the first contact hole 155.

Moreover, in the unit on-off pad part 230, a lower metal 270 and thepixel electrode 190 are formed inside the first contact hole 155.

Here, the lower metal 270 of the unit on-off pad part 230 may be formedof metal that is used when forming the touch sensing line formed in thepixel area. As another example, the lower metal 270 of the unit on-offpad part 230 may be formed of a transparent conductive material that isused when forming the common electrode formed in the pixel area.

The unit on-off pad part 230 is formed for a contact instead of anelectrode to which a pixel voltage for image display is supplied. Thepixel electrode 190 of the unit on-off pad part 230 is formed of thesame material as that of the pixel electrode in the pixel area whenforming the pixel electrode.

The pixel bar 234 and the pixel pad 232 are formed apart from eachother, and thus are not directly connected. The pixel bar 234 and thepixel pad 232 are connected through the lower metal 270 and the contactpattern 260.

To this end, the second contact hole 185 is formed in the secondpassivation layer 180 formed on the pixel bar 234. A contact pattern 260is formed to contact the pixel bar 234, in the second contact hole 185.Furthermore, the contact pattern 260 is formed to contact the lowermetal 270, in the first contact hole 155.

In this way, the pixel bar 234 and the pixel pad 232 are connected usingthe contact pattern 260.

Here, the contact pattern 260 is formed of a transparent conductivematerial, on the same layer as that of the common electrode 160 in thepixel area. A contact between the pixel bar 234 and the pixel pad 232 isformed by connecting the contact pattern 260 to the lower metal 270connected to the pixel pad 232.

The pixel bar 234 is formed to have a width of 20 um and a length of 36um. The pixel bar 234 is formed to be separated by a distance of 5 umfrom the first contact hole 155 so as not to overlap the first contacthole 155.

The second contact hole 185 formed on the pixel bar 234 may be formed ina 6 um×6 um size.

The second contact hole 185 is formed in the first contact hole 155inside the unit on-off pad part 230. In this case, the second contacthole 185 is formed to have a size similar to that of the lower metal270. One side of the lower metal 270 is formed to have a size less by 10um than that of the second contact hole 185, such that a contact betweenthe lower metal 270 and the contact pattern 260 is smoothly made.

Here, to prevent the contact of the pixel bar 234 from being broken at aboundary surface of the first contact hole 155, the lower metal 270 isused as a bridge for a contact between the pixel bar 234 and the pixelpad 232. Comparing with the related art, the length of the lower metal270 of the present invention is expanded, and thus the lower metal 270contacts the pixel bar 234 with the pixel pad 232.

A contact area of the pixel bar 234 uses a clear area in a manufacturingprocess. In this case, the clear area is formed to have a size less thanthat of the lower metal 270. When forming the second contact 185 byetching the second passivation layer 180, the lower metal 270 act as anetch stop.

Comparison between relative sizes of respective elements is as follows.The clear area of the first passivation layer is the greatest size, andthe lower metal 270 has the second greatest size. The pixel electrode190 has the smallest size. The pixel electrode 190 and the clear area ofthe second passivation layer 180 have the same size. That is, the cleararea of the first passivation layer (PAS1)>the lower metal >the pixelelectrode=the clear area of the second passivation layer (PAS2).

Even in the unit FPC pad/unit FPC shorting connection part 240 and thebump input dummy/bump output dummy part 250, identically to the uniton-off pad part 230, contacts between pad patterns and a signal line(shorting bar) may be made using the lower metal 270 and the contactpattern 260 as a bridge.

In the pad part of the LCD device (having the above-described structure)according to an embodiment of the present invention, the second contacthole 185 is formed in the pixel bar 234, and the pixel bar 234 may beconnected to the pixel pad 232 in the pad area by using the lower metal270 and the contact pattern 260 as a bridge. Therefore, the secondpassivation layer 180 and the pixel electrode 190 can be simultaneouslyformed using the half tone mask, and a defective contact can beprevented in the pad area.

FIGS. 11 to 15 are views illustrating a method of manufacturing an LCDdevice according to an embodiment of the present invention. Here, FIGS.11 to 15 illustrate a manufacturing process with respect to a sectionalsurface along line A1-A2 and line B1-B2 of FIG. 9. In FIGS. 11 to 15, amanufacturing method of forming a pixel in the active area is notillustrated.

Hereinafter, the method of manufacturing the LCD device according to anembodiment of the present invention will be described with reference toFIGS. 11 to 15. A sectional view taken along line A1-A2 illustrates aportion corresponding to one pixel pad in the pad area. A sectional viewtaken along line B1-B2 illustrates a portion corresponding to one pixelpad in the pad area.

Referring to FIG. 11, the first passivation layer (PAS1) 150 is formedin a pad area and a contact area. Subsequently, a clear area is formedby an etching process and a photolithography process using a half tonemask.

The first contact hole 155 is formed through the clear area of the firstpassivation layer (PAS1) 150. Here, the first passivation layer 150 maybe formed of photo acryl, and have a thickness of 3 um.

Subsequently, the lower metal 270 is formed in the clear area of thecontact area and the pad area. In this case, the lower metal 270 formedin the contact area is expanded in size, and thus formed on the firstpassivation layer 150 in a normal area as well as the clear area.

The lower metal 270 of the unit on-off pad part 230 may be formed of atleast one of the transparent conductive material of the common electrodeand the metal of the touch sensing line formed in the pixel area.

Here, in a subsequent process, the lower metal 270 acts as an etch stopof the second contact hole 185 that is formed by etching the secondpassivation layer 180.

Subsequently, referring to FIG. 12, the second passivation layer (PAS2)180 is formed to cover the first passivation layer 150 and the lowermetal 270. Here, the second passivation layer 180 may be formed of SiO₂or SiNx, and have a thickness of 2,000 Å to 3,000 Å.

Subsequently, referring to FIG. 13, a photoresist 195 is coated on thesecond passivation layer 180, and then, the etching process and thephotolithography process using the half tone mask are performed.

In the pad area, an area overlapping the lower metal 270, namely, thephotoresist 195 on the first contact hole 155 is removed, therebyforming a clear area. In this case, the clear area is formed to have asize less than that of the lower metal 270.

In the contact area, the photoresist 195 on the first contact hole 155is removed, thereby forming a clear area.

In the photoresist 195 in an area overlapping the normal area of thefirst passivation layer 150, a portion overlapping the lower metal 270is removed to form the clear area, and the other portion is formed as ahalf tone area.

A top of the second passivation layer 180 is exposed by the clear areasthat are respectively formed in the pad area and the contact area.

Subsequently, referring to FIG. 14, the second passivation layer 180exposed by the clear area is removed by performing an ashing process,thereby exposing the lower metal 270.

Specifically, the second passivation layer 180 in the clear area isremoved in the pad area, and thus, the second contact hole 185 isformed. The lower metal 270 is exposed by the second contact hole 185.

Moreover, the second passivation layer 180 in the clear area is removedin the contact area, and thus, the second contact hole 185 is formed. Inthis case, as illustrated in FIGS. 9 and 10, the second contact hole 185formed in the contact area is formed on the pixel bar 234 to expose thepixel bar 234.

The second contact hole 185 formed on the pixel bar 234 is formed tohave a 6 um×6 um size.

The first contact hole 155 and the second contact hole 185 are formedusing a clear area of a half tone mask.

Subsequently, referring to FIG. 15, the pixel electrode 190 is formed ofa transparent conductive material such as ITO, in the pad area.

Moreover, the contact pattern 260 is formed of a transparent conductivematerial such as ITO, in an outer portion of the pad area and thecontact area.

Here, the pixel bar 234 in the contact area and the pixel pad 232 in thepad area are formed apart from each other, and thus are not directlyconnected. The pixel bar 234 in the contact area and the pixel pad 232in the pad area are connected through the lower metal 270 and thecontact pattern 260.

As described above, the second contact hole 185 is formed at the secondpassivation layer 180 formed on the pixel bar 234, and the pixel bar 234and the pixel pad 232 are connected using the contact pattern 260 as abridge.

The contact pattern 260 is formed of a transparent conductive material,on the same layer as that of the common electrode 160 in the pixel area.The contact pattern 260 is connected to the lower metal 270 connected tothe pixel pad 232. Therefore, the pixel bar 234 contacts the pixel pad232.

The pixel bar 234 is formed to have a width of 20 um and a length of 36um. The pixel bar 234 is formed to be separated by a distance of 5 umfrom the first contact hole 155 so as not to overlap the first contacthole 155.

The second contact hole 185 is formed to have a size similar to that ofthe lower metal 270. One side of the lower metal 270 is formed to have asize less by 10 um than that of the second contact hole 185, such that acontact between the lower metal 270 and the contact pattern 260 issmoothly made.

To prevent the contact of the pixel bar 234 from being broken at aboundary surface of the first contact hole 155, the lower metal 270 isused as a bridge for a contact between the pixel bar 234 and the pixelpad 232.

Comparing with the related art, the length of the lower metal 270 of thepresent invention is expanded, and thus the lower metal 270 contacts thepixel bar 234 with the pixel pad 232.

The lower metal 270 that acts as a bridge for contact of the pixel bar234 may be expanded in length to a lower portion of the pixel bar 234.In this case, the length of the lower metal 270 may be expanded usingboth the metal of a conductive line and the transparent conductivematerial of the common electrode. As another example, the length of thelower metal 270 may be expanded using only one of the metal of theconductive line and the transparent conductive material of the commonelectrode.

Comparison between relative sizes of respective elements is as follows.The clear area of the first passivation layer is the greatest size, andthe lower metal 270 has the second greatest size. The pixel electrode190 has the smallest size.

The pixel electrode 190 and the clear area of the second passivationlayer 180 have the same size. That is, the clear area of the firstpassivation layer (PAS1)>the lower metal >the pixel electrode=the cleararea of the second passivation layer (PAS2).

According to another embodiment of the present invention, even in theunit FPC pad/unit FPC shorting connection part 240 and the bump inputdummy/bump output dummy part 250, identically to the unit on-off padpart 230, contacts between pad patterns and a signal line (shorting bar)may be made using the lower metal 270 and the contact pattern 260 as abridge.

The sizes of the second contact hole 185 and pixel pad 232 in the secondpassivation layer 185 formed in the pad area may be changed, in whichcase the sizes are required to be sizes in which a test is capable ofbeing performed with a probe tip.

In the LCD device and the method of manufacturing the same according tothe first embodiment of the present invention, the second passivationlayer 180 and the pixel electrode 190 are simultaneously formed by thesingle mask process using the half tone mask, and thus, manufacturingefficiency increases.

Moreover, in forming the pixel electrode 190, the present invention canprevent disconnection of the pixel bar 234, caused by loss of the pixelelectrode 190 due to the lift-off process, in the pad area. Accordingly,the present invention can enhance the contact performance of the pixelbar 234 in the pad area.

FIG. 16 is a view illustrating a pixel structure of an LCD deviceaccording to a second embodiment of the present invention. In FIG. 16, atouch sensor is illustrated as being internalized in an in-cell touchtype in the TFT array substrate. In FIG. 16, a color filter arraysubstrate (upper substrate), a liquid crystal layer, a backlight unit,and a driving circuit part are not illustrated. The pixel structure ofFIG. 8 is similar to that of FIG. 16, and thus, a detailed descriptionon the same element is not provided.

Referring to FIG. 16, a TFT array substrate includes a glass substrate110, a light shield 120, a buffer layer 122, a gate insulator 136, adata contact 145, a inter-layer dielectric (ILD) 140, a firstpassivation layer 150, a common electrode 160, a touch sensing line 170,a first contact line 160 a, a second contact line 170 a, a secondpassivation layer 180, a pixel electrode 190, and a TFT that includes anactive 130, a source 132, an LDD 133, a drain 134, and a gate 138.

A portion of the gate insulator 136 and a portion of the inter-layerdielectric 140 are etched to expose a top of the drain 134. The datacontact 145 is formed at a portion in which the gate insulator 136 andthe inter-layer dielectric 140 are etched.

The data contact 145 contacts the drain 134 and the pixel electrode 190.The first passivation layer (PAS1) 150 is formed to cover the datacontact 145, on the inter-layer dielectric 140.

The common electrode 160 is formed on the first passivation layer 150,in a pixel area.

The touch sensing line 170 is formed on the common electrode 160 tocross a plurality of pixels, and connects the common electrodes 160 ofadjacent pixels. Therefore, the common electrode 160 acts as a touchsensing electrode during a non-display period.

The first and second contact lines 160 a and 170 a are formed on thedata contact 145. The first and second passivation layers 150 and 180are etched to expose a top of the data contact 145, thereby forming acontact hole. The first and second contact lines 160 a and 170 a areformed inside the contact hole.

Here, the first contact line 160 a is formed of the same material asthat of the common electrode 160 simultaneously with the commonelectrode 160 during a manufacturing process. The second contact line170 a is formed of the same material as that of the touch sensing line170 simultaneously with the touch sensing line 170 during themanufacturing process.

The first and second contact lines 160 a and 170 a are formed insularly,and thus, a signal and a voltage are not supplied thereto. That is, thefirst and second contact lines 160 a and 170 a act as a via between thedata contact 145 and the pixel electrode 190.

A second passivation layer 180 is formed to cover the common electrode160 and the touch sensing line 170, on the first passivation layer 150.

A first contact hole 155 is formed in an area overlapping the datacontact 145, in the first passivation layer 150.

The second passivation layer 180 is etched to form a second contact hole185, on the first contact hole 155.

The pixel electrode 190 is formed in a finger shape in the pixel area,on the second passivation layer 180. The pixel electrode 190 is formedin the first and second contact holes 155 and 185, and contacts the datacontact 145.

The second passivation layer 180 and the pixel electrode 190 may besimultaneously formed by a single mask process by using one half tonemask (HTM).

FIG. 17 is a view illustrating a pad part of an LCD device according toa second embodiment of the present invention. FIG. 18 is an enlargedview of a contact area of the pad part of FIG. 17. FIG. 19 is asectional view taken along line A1-A2 and line B1-B2 of FIG. 17.

In FIGS. 17 to 19, a unit FPC pad/unit FPC shorting connection part 240among a plurality of pad parts 230, 240 and 250 is illustrated.

Referring to FIGS. 17 to 19, the unit FPC pad/unit FPC shortingconnection part 240 among the pad parts 230, 240 and 250 includes aplurality of pads 242, a plurality of pixel bars (pixel lines) 244, anda power line 246.

The unit FPC pad/unit FPC shorting connection part 240 includes a padarea in which the pads 242 are formed, and a contact area in which thepixel bar 244 contacts the pad 242.

The unit FPC pad/unit FPC shorting connection part 240 is formed by amanufacturing process of forming a plurality of pixels. Here, the unitFPC pad/unit FPC shorting connection part 240 has a structure in which apad pattern for supplying a signal to a pixel are arranged in each ofthe pads 242.

Moreover, a lower metal 270 and the pixel electrode 190 are formed inthe contact area of the unit FPC pad/unit FPC shorting connection part240. In this case, the lower metal 270 and pixel electrode 190 formed inthe contact area are formed apart from the first contact hole 155.

The pixel bar 244 and pad 242 of the unit FPC pad/unit FPC shortingconnection part 240 are formed to be separated from each other, and thusare not directly connected. The pixel bar 244 and the pad 242 areconnected through a bridge layer 280 that is configured with the contactpattern 260 and the lower metal 270.

The bridge layer 280 may be configured with the contact pattern 260 andthe lower metal 270.

The contact pattern 260 and the common electrode 160 in the pixel areamay be formed on the same layer. The contact pattern 260 is formed of atransparent conductive material (ITO) which is the material of thecommon electrode 160.

The lower metal 270 may be formed using the metal of the touch sensingline 170 formed in the pixel area. When forming the touch sensing line170, the lower metal 270 is formed of the same material as that of thetouch sensing line 170.

To connect the pixel bar 244 and the pad 242, the second contact hole185 is formed in the second passivation layer 180 on the pixel bar 244.The pixel electrode 190 is formed on the second passivation layer 180and in the second contact hole 185. The contact pattern 260 is formed inthe first contact hole 155. The lower metal 270 is formed on the contactpattern 260, in an area in which the second contact hole 185 is formed.That is, the contact pattern 260 and the lower metal 270 are stacked inan area in which the second contact hole 185 is formed. In this way, thepixel bar 244 and the pad 242 are connected with the bridge layer 280that is configured with the contact pattern 260 and the lower metal 270.

When simultaneously forming the second passivation layer 180 and thepixel electrode 190 in an etching process, a lift-off process, and aphotolithography process using a half tone mask, the pixel electrode 190may be lost in the contact area. However, even when the pixel electrode190 is lost in the contact area, a contact is not disconnected becausethe pixel bar 244 and the pad 242 are connected with the bridge layer280.

Here, the pixel bars 234 are formed to be separated by a distance of 10um to 20 um from each other so as not to overlap the first contact hole155.

The second contact hole 185 formed on the pixel bar 234 may be formed ina 6 um×6 um size.

The second contact hole 185, as illustrated in FIG. 17, may be formed asone on one pixel bar 244, but is not limited thereto. To more enhancethe contact performance of the pixel bar 244, as illustrated in FIG. 18,a plurality of the second contact holes 185 may be formed in one pixelbar 244.

A contact area of the pixel bar 234 is formed using a clear area in amanufacturing process. In this case, the clear area is formed to have asize less than that of the lower metal 270. When forming the secondcontact 185 by etching the second passivation layer 180, the lower metal270 act as an etch stop.

As illustrated in FIG. 19, the second contact hole 185 formed in thecontact area is formed to have a size less than that of the lower metal270. As an example, the second contact hole 185 is formed to have a sizeless by 10 um than that of one side of the lower metal 270.

In addition to the unit FPC pad/unit FPC shorting connection part 240,the unit on-off pad part 230 and the bump input dummy/bump output dummypart 250 may also connect the pad 242 and the pixel bar 244 by using theabove-described bridge layer 280.

In the pad part of the LCD device (having the above-described structure)according to an embodiment of the present invention, the second contacthole 185 is formed in the pixel bar 244, and the pixel bar 234 may beconnected to the pixel pad 232 in the pad area by using the bridge layer280 configured with the lower metal 270 and the contact pattern 260.Therefore, the second passivation layer 180 and the pixel electrode 190can be simultaneously formed using the half tone mask, and the defectivecontact of the pixel bar 244 can be prevented in the pad area.

FIGS. 20 to 24 are views illustrating a method of manufacturing an LCDdevice according to an embodiment of the present invention.

FIGS. 20 to 24 illustrate a manufacturing process with respect to asectional surface along line A1-A2 and line B1-B2 of FIG. 17. In FIGS.20 to 24, a manufacturing method of forming a pixel in the active areais not illustrated.

Hereinafter, the method of manufacturing the LCD device according to anembodiment of the present invention will be described with reference toFIGS. 20 to 24. A sectional view taken along line A1-A2 illustrates aportion corresponding to one pixel pad in the pad area. A sectional viewtaken along line B1-B2 illustrates a portion corresponding to one pixelpad in the pad area.

Referring to FIG. 20, the first passivation layer (PAS1) 150 is formedin a pad area and a contact area.

Subsequently, in the contact area, a portion of the first passivationlayer (PAS1) 150 is etched by performing an etching process and aphotolithography process using a half tone mask. The etched portion ofthe first passivation layer 150 becomes the first contact hole 155. Thefirst passivation layer 150 may be formed using the clear area of thehalf tone mask.

In this case, the first passivation layer 150 may be formed of photoacryl, and have a thickness of 3 um.

Subsequently, the bridge layer 280 is formed by sequentially forming thecontact pattern 260 and the lower metal 270 in the pad area and thecontact area.

In this case, in the contact area, the contact pattern 260 is formed onthe first passivation layer 150 and in the first contact hole 155 area.The lower metal 270 is formed only on the first passivation layer 150.

Here, in a subsequent process, the lower metal 270 acts as an etch stopof the second contact hole 185 that is formed by etching the secondpassivation layer 180.

Subsequently, referring to FIG. 21, the second passivation layer (PAS2)180 is formed on the first passivation layer 150 and in the firstcontact hole 155 area. Here, the bridge layer 280 is covered by thesecond passivation layer 180. The second passivation layer 180 may beformed of SiO₂ or SiNx, and have a thickness of 2,000 Å to 3,000 Å.

Subsequently, referring to FIG. 22, a photoresist 195 is coated on thesecond passivation layer 180, and then, the etching process and thephotolithography process using the half tone mask are performed.

In the pad area, a portion of the photoresist 195 partially overlappingthe bridge layer 280 is removed, thereby forming a clear area. In thiscase, the clear area is formed to have a size less than that of thelower metal 270.

In the contact area, a portion of the photoresist 195 partiallyoverlapping the bridge layer 280 is removed, thereby forming a cleararea.

A portion of the photoresist 195 that does not overlap the bridge layer280 forms a half tone area or a normal area.

A top of the second passivation layer 180 is exposed by the clear areasthat are respectively formed in the pad area and the contact area.

Subsequently, referring to FIG. 23, the second passivation layer 180exposed by the clear area is removed by performing an ashing process,thereby exposing the bridge layer 280.

Specifically, the second passivation layer 180 in the clear area isremoved in the pad area, and thus, the second contact hole 185 isformed. The bridge layer 280 is exposed by the second contact hole 185.

Moreover, the second passivation layer 180 in the clear area is removedin the contact area, and thus, the second contact hole 185 is formed. Inthis case, the second contact hole 185 formed in the contact area isformed on the pixel bar 244 to expose the pixel bar 244.

The second contact hole 185 formed on the pixel bar 234 is formed tohave a 6 um×6 um size.

The second contact hole 185, as illustrated in FIG. 17, may be formed asone on one pixel bar 244, but is not limited thereto. To more enhancethe contact performance of the pixel bar 244, as illustrated in FIG. 18,a plurality of the second contact holes 185 may be formed in one pixelbar 244.

The first contact hole 155 and the second contact hole 185 are formedusing a clear area of a half tone mask.

Subsequently, referring to FIG. 24, the pixel electrode 190 is formed ofa transparent conductive material such as ITO, in the pad area.

Moreover, the pixel electrode 190 is formed of a transparent conductivematerial such as ITO, in an outer portion of the pad area and thecontact area.

Here, the pixel bar 244 in the contact area and the pad 242 in the padarea are formed apart from each other, and thus are not directlyconnected. The pixel bar 234 in the contact area and the pixel pad 232in the pad area are connected through the bridge layer 280.

Accordingly, by performing the lift-off process for simultaneouslyforming the second passivation layer 180 and the pixel electrode 190, acontact between the pad 242 and the pixel bar 244 is not disconnectedeven when the pixel electrode 190 is partially lost in the pad area.

Here, the pixel bar 234 is formed to be separated by a distance of 20 umfrom the first contact hole 155 so as not to overlap the first contacthole 155.

The second contact hole 185 formed in the contact area is formed to havea size less than that of the lower metal 270. As an example, the secondcontact hole 185 is formed to have a size less by 10 um than that of oneside of the lower metal 270.

To prevent the contact of the pixel bar 234 from being broken at aboundary surface of the first contact hole 155, by expanding the lengthof the contact pattern 260 in the bridge layer 280 in the contact area,the contact pattern 260 is used as a bridge for a contact between thepixel bar 244 and the pixel pad 242.

The contact pattern 260, as a bridge for contact of the pixel bar 244,may be expanded in length to a lower portion of the pixel bar 234. Inthis case, the contact pattern 260 may be formed using all transparentmetals of the common electrode.

In addition to the unit FPC pad/unit FPC shorting connection part 240,the unit on-off pad part 230 and the bump input dummy/bump output dummypart 250 may also connect the pad 242 and the pixel bar 244 by using theabove-described bridge layer 280.

The sizes of the second contact hole 185 and pad 242 in the secondpassivation layer 185 formed in the pad area may be changed, in whichcase the sizes are required to be sizes in which a test is capable ofbeing performed with a probe tip.

In the LCD device and the method of manufacturing the same according tothe second embodiment of the present invention, the second passivationlayer 180 and the pixel electrode 190 are simultaneously formed by thesingle mask process using the half tone mask, and thus, manufacturingefficiency increases.

Moreover, in forming the pixel electrode 190, the present invention canprevent disconnection of the pixel bar 244, caused by loss of the pixelelectrode 190 due to the lift-off process, in the pad area. Accordingly,the present invention can enhance the contact performance of the pixelbar 244 in the pad area.

FIG. 25 is a view illustrating a plurality of masks that are used in aschematic manufacturing method and process of an LCD device withintegrated touch sensor.

Referring to FIG. 25, in the related art, a total of eleven masks arerequired in manufacturing a TFT array substrate with built-in touchsensor, but the number of masks can decrease by one or two in themanufacturing methods according to the first and second embodiments ofthe present invention.

Specifically, as illustrated in FIG. 25A, by forming the secondpassivation layer (PAS2) and a pixel electrode (PXL) with one half tonemask, the number of used masks can decrease by one compared to therelated art. Accordingly, a TFT array substrate with built-in touchsensor can be manufactured with a total of ten masks.

Moreover, as illustrated in FIG. 25B, by forming the second passivationlayer (PAS2) and a pixel electrode (PXL) with one half tone mask andforming a common electrode and a touch sensing line with one mask, thenumber of used masks can decrease by two compared to the related art.Accordingly, a TFT array substrate with built-in touch sensor can bemanufactured with a total of nine masks.

Accordingly, in manufacturing a TFT array substrate with built-in touchsensor, the number of masks can decrease, the manufacturing cost can besaved, and a time taken in manufacturing can be shortened.

As described above, the method of manufacturing the LCD devicesimultaneously forms the passivation layer and the pixel electrode inthe single mask process using the half tone mask, and thus can increasemanufacturing efficiency.

The method of manufacturing the LCD device can prevent disconnection,caused by loss of a pixel electrode due to the lift-off process, in thepad area.

In the LCD device and the method of manufacturing the same, the contactperformance of the pixel bar can be enhanced in the pad area.

In addition to the aforesaid features and effects of the presentinvention, other features and effects of the present invention can benewly construed from the embodiments of the present invention.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A method of manufacturing a liquid crystaldisplay (LCD) device including a pad area with a pixel pad formedtherein and a contact area with a pixel bar formed therein, the methodcomprising: forming a first passivation layer in the pad area and thecontact area, and removing a portion of the first passivation layer toform a first contact hole; forming a lower metal inside the firstcontact hole and on the first passivation layer in the contact area;forming a second passivation layer to cover the first passivation layerand the lower metal; removing a portion of the second passivation layeroverlapping the pixel bar in the contact area to form a second contacthole and removing another portion of the second passivation layeroverlapping the lower metal in the first contact hole to form a thirdcontact hole; and coating a transparent conductive material on the padarea to form a pixel electrode, and coating a transparent conductivematerial on the contact area to form a contact pattern, wherein thepixel pad and the pixel bar are connected with the contact pattern andthe lower metal.
 2. The method of claim 1, wherein the first and secondcontact holes are formed using a clear area of a half tone mask.
 3. Themethod of claim 1, wherein, when forming a touch sensing line in anactive area, the lower metal is formed of the same material as the touchsensing line, or when forming a common electrode in the active area, thelower metal is formed of the same material as the common electrode. 4.The method of claim 1, wherein the second contact hole is formed to havea size in which a test is capable of being performed with a probe tip.5. The method of claim 1, wherein the lower metal acts as an etch stopin etching the second passivation layer.
 6. The method of claim 1,wherein the forming of a second contact hole comprises: coating aphotoresist on the second passivation layer, and forming a normal area,a half tone area, and a clear area by performing an etching process anda photolithography process using a half tone mask; and removing thesecond passivation layer through the clear area to form the secondcontact hole.
 7. The method of claim 1, wherein, when forming a commonelectrode in an active area, the contact pattern is formed of the samematerial as the common electrode, and when forming a touch sensing linein the active area, the lower metal is formed of the same material asthe touch sensing line.
 8. The method of claim 1, wherein the lowermetal extends to the first contact hole to connect the pixel bar to thepixel pad.
 9. The method of claim 1, wherein the pixel electrode isconnected to the lower metal via the third contact hole.
 10. The methodof claim 1, wherein the contact pattern extends to the pad area andcontacts the lower metal via the third contact hole.
 11. The method ofclaim 1, wherein the pixel electrode contacts the lower metal via thesecond contact hole.
 12. The method of claim 1, wherein the contactpattern extends to the first contact hole, and wherein the lower metalis formed on the contact pattern in the contact area.
 13. The method ofclaim 12, wherein the pixel electrode contacts the lower metal via thesecond contact hole.
 14. The method of claim 1, wherein the secondpassivation layer has at least one other contact hole in the pixel barin addition to the second contact hole to further expose the lowermetal.
 15. The method of claim 1, wherein the first contact hole has alarger area than the lower metal in the first contact hole in plan view,and wherein the lower metal has a larger area than the third contacthole in plan view.